Automatic feed mechanisms



Oct. 9, 1951 R. E. PRICE 2,570,592

- AUTOMATIC FEED MECHANISMS Filed Jan. '7, 1949 2 Sheets-Sheet l RALPHPRICE (lttorneu PRICE AUTO TIC lled Jan r 49 F] I I00 0 RA PH CEPatented Oct. 9, 1951 AUTOMATIC FEED MECHANISMS Ralph E. Price,HighfieluLMd; assignor to Landis Tool 00., Waynesboro, Pa.

Application January 7, 1949, Serial No. 69,711

- Claims.

larly to feed mechanisms operable automatically in definite relation tothe Work traverse movement of the machine.

The machine for which this invention is intended has a feed mechanismconsisting of a feedscrewmoved axially by power for a rapid .feedmovement as well as power operated means for rotating a feedscrew foraslow'fed movement. In order to effect automatic adjustment of thefeedscrew at each end of the traverse movement, the power means, in thiscase a piston and cylinder operable through a rack and pinion, must bemoved a slight but measured distance. It is also desirable that thismovement be adjustable. We prefer to accomplish this by providing afixed maximum volume of fluid for actuating the feed piston andthrottling this supplyin order to adjust the increment of feed. It is,therefore, an object of this invention to provide a shuttle valveoperable in timed relation with the reversing mechanism of a'grindingmachine for causing incremental movement of a feed mechanism.

It is a further object to provide means for modifying the function ofsaid shuttle valve by means of a selector valve which may be positionedto provide incremental feed at feith'er' 'or both ends of the traversemovement or to substitute a continuous feed movement in the absence of atraverse movement when said'shuttle valve is rendered inoperative.

Figure 1 is a hydraulic diagram of the relative arrangement of partsnecessary to carry out the object of the invention.

Figure 2 is a section through the selector valve showing the means forlocating the valve in various positions.

Figure 3 is a longitudinal sectional of the selector valve.

Figure *4 is a series-of sections taken through the selector valve invarious angularpositions thereof. l

While this invention relates to grinding-ma} chines, it is not limitedto such apparatus but may be applied to any machines having comparablefunctions. Since the invention deals primarily with hydraulic apparatus,it is not considered necessary to include in the drawings details ofmachine structure. The drawings, thereelevation fore, have been limitedto the apparatus essential to the operation of the invention.

The means for producing a traverse movement consists of a cylinder I0 inwhich a piston II is slidably mounted with a double piston rod I2 extending from each end of said cylinder. Fluid under pressure is directedfrom a pump [5 through line it, throttle valve I1 and line l8 toreversing valve I9 from which it is directed automatically to oppositeends of cylinder l0 through lines 20 and 2|.

Said reversing valve may be shifted by fluid under pressure directedautomatically to opposite ends thereof by pilot valve 25 which receivesfluid under pressure from line I8 through line 26. Said pilot valve isshown as being actuated by means of a lever 27. Said fiuid is directedauto.- matically through lines and 3] to opposite ends of valve I9. Atthe same time said fluid is directed automatically through lines and 36to opposite ends of an automatic feed valve 40. Valve receives fluidunder pressure from pump I5 through line I6, line 45, choke coil 46 andline 47. The purpose of said choke coil'is to limit the flow of fluid toshuttle valve 53 and thus prevent too rapid operation thereof. Pressurein line 46 exceeds that in line I8 by the drop across throttle valve I1.Said fluid is directed alternately through lines 50 and 5| to oppositeends of cylinder 52 in which is slidably mounted a piston type shuttlevalve 53. Auto feed valve 40 also directs fluid alternately fromopposite ends of said shuttle valvethrough lines and BI to a selectorvalve 10, which will be described later. The pressure of the fluidsupplied to cylinder I0 is determined by a fluid operated relief valve15 of the type disclosed in Patent 2,456,431, granted December 14, 1948.

The portion of the feed mechanism with which ,we are concerned consistsof a feedscrew hav ing gear teeth thereon engaging rack teeth 82 onpiston rod 83. .Said piston rod is attached to a piston 84 slidablymounted in cylinder 85. Further details of this feed mechanism may befound in Price Patent 2,313,479, issued March 9, 1943. Fluid underpressure for actuating said piston may be supplied from pump I5 throughline I8 and line to selector valve IE! and .then through line 9| fromsaidselector valve to the right-hand end of cylinder 85. Fluid may alsobe supplied to said selector valve from shuttle valve 53, as describedabove. 1

The selector valve consists of a housing H30 and a rotatable valvemember Ill having a knob I92. Said valve member is hollow and has athrottle valve M5 in one end, which is adjustable by means of a knob106. At the other end is a relief valve consisting of a ball H0 urged byspring III into closing engagement of said valve member. Said valve isheld against axial movement by a screw II5 engaging an annular slot I H3in the valve member. Said valve may be adjusted angularly to fourdifferent positions determined by four peripherally spaced slots ornotches I into which a ball I2I is pressed by spring 22 to position saidvalve member. Said valve member is divided into four sections:

Section AA has an annular groove I connected to the hollow portion ofthe valve member by a radial passage I26. Section BB consists of twocircumferential slots I and I3I on the valve member substantially atright angles to one another. Section CC consists of a passage Idiametrically through the valve member and a second passage I36 radiallyof said valve member and at an angle to passage I35. Said section alsohas a circumferential slot I3I. similar to section AA in that itconsists of a circumferential groove I40 connected to the hollow portionof the valve member by radial passage I II.

Operation The operation of the traverse and reversing mechanismdescribed herein is well known and need not be repeated here.

The operation of the feed mechanism is dependent upon the operation ofthe reversing mechanism modified by the setting of selector valve I0.

Regardless of the setting of valve I0, automatic feed Valve 40 andshuttle valve 53 are actuated each time the reversing mechanismfunctions.

Section DD is Automatic feed valve 40 performs a double function: Itdirects fluid under pressure from high pressure line 47 automaticallythrough lines 50 and 5I to opposite ends of shuttle valve 53. Whilevalve 40 is directing the fluid under pressure from line 4'I to one endor the other of valve 53, it is also directing the fluid discharged fromthe opposite end of said shuttle valve through lines 60 or BI toselector valve I0. Whether the fluid thus directed to said selectorvalve is utilized to efiect incremental movement of slow feed piston 84is dependent upon the setting of said valve I0.

Valve I05 detetrmines the magnitude of said increment. Said valve may beadjusted to permit the passage of any or all of the measured amount offluid discharged by shuttle valve 53. When valve I05 is so adjusted thatonly a portion of this fluid is used to effect the feed movement, theunused fluid escapes through relief valve H0 and radial passage I26 insection AA of valve I0 from which it is discharged through line 90 intothe low pressure line I8. Thus, the pressure at which fluid is suppliedto said cylinder 85 from line 9| is the resultant of the pressure ofspring I II and the machine pressure in line I8.

Valve I0 may be set in any one of four angular positions. In the firstof these, when the carriage drive piston II is reversed at the left-handend of its movement, automatic feed valve 40 is in its right-handposition, and the discharge from the right-hand end of shuttle valve 53passes through line 5|, valve 40 and line 6| to radial passage I36 andsection CC of valve 70. From passage I36, said fluid is conductedthrough throttle valve I05 and radial passage MI in section DD of saidvalve to line 9| leading to the head end of feed cylinder 85.

When the movement of piston I I is reversed at the right-hand end of itstravel, valve 40 is in its left-hand position as shown in Figure 1. Inthis position the measured amount of fluid discharged from the left-handend of valve 53 through line 50, valve 40 and line 60 enters acircumferential slot I31 in section CC. Slot I31 in section CC isconnected by a port I50 to a similar slot I30 in section BB. In thefirst position of valve I0, slot I30 is connected with an exhaustpassage I53; and thus when piston I I is reversedat the righthand end ofits travel, the measured amount of fluid discharged from shuttle valve53 is exhausted and no feed impulse is given to the feed piston 84.

In the Number 2 position of valve I0, passage I35 in section CC is inline with both of the lines 60 and 6|; and thus the measured quantity offluid discharged from either end of shuttle valve 53 is directed throughthrottle valve I05, as described above, to the head end of said cylinder85.

It might be well at this point to call attention to the fact thatsections AA and DD of valve I0 function in the same manner regardless ofthe angular position of said valve.

In the Number 3 position of valve 10 neither of the lines 60 nor 6| isconnected to supply fluid to the center passage of said valve. However,fluid from the machine pressure line enters port I60 of section AA andBB through slot'I3I in section BB to port I6I in section BB. Port IIiIis connected with the center portion of the valve through passage I35,and thus a continuous supply of fluid may be directed through throttlevalve I05 and line 9| to complete a continuous or plunge cut feedingmovement of piston 84.

In the Number 4 position of valve III, the measured quantity of fluidfrom the left end of shuttle valve 53 passes through line 50, valve 40and line 66 to radial passage I36 in section CC of valve I0. Frompassage I36 said fluid is directed through throttle valve I05 and line9I to the head end of said cylinder 85. This occurs when piston II isreversed at the right-hand end of its travel. When reversal occurs atthe left-hand end of the piston movement, the measured amount of fluidfrom the right-hand end of valve 53 passes through line 5|, valve 40 andline 6|. Line BI is connected to the center portion of valve I0. It isconnected to slot I31 in section CC. In this position of the valve, slotI3! is connected through port IIiI to slot I30 in section BB. Slot I30in the number four position of valve I6 connects port I6I with exhaustpassage I53. Thus, actuation of the feed mechanism occurs only at thright-hand reversal.

I claim:

1. In a grinding machine having a work sup port and a grinding wheelsupport, means for effecting relative transverse and longitudinalmovement between said supports, said transverse moving means comprisinga feedscrew and nut, a hydraulic motor for rotating one of said members,a reversing mechanism for said longitudinal moving means, an automaticfeedvalve actuated by said reversing mechanism, a shuttle valve of fixedcapacity in excess of maximum requirements actuated by said automaticfeed valve for supplying a measured maximum quantity of fluid underpressure to said feedscrew operating motor at each reversal of saidlongitudinal moving means and a selector valve between said shuttlevalve and said screw operating motor for preventing operation thereof atone or both ends of the movement of said longitudinal moving means, saidselector valve having means for predetermining whether all or a portionof said measured quantity of fluid reaches said feedscrew operatingmotor, and a relief valve for 3 lay-passing the unused portion of saidmeasured quantity of fluid.

2. In a grinding machine having a work support and a grinding wheelsupport, means for effecting relative transverse and longitudinalmovement between said supports,said transverse moving means comprising afeedscrew and nut, a hydraulic motor for rotating one of said members, areversing mechanism for said longitudinal moving means, an automaticfeed valve actuated by said reversing mechanism, a shuttle valve offixed capacity in excess of maximum requirements actuated by saidautomatic feed valve for supplying a measured maximum quantity of fluidunder pressure to said feedscrew operating motor at each reversal of themovement of said longitudinal moving means, a selector valve betweensaid shuttle valve and said screw operating motor for preventingoperation thereof at one or both ends'of said longitudinal movement, anda restriction in the supply of fluid to said shuttle valve to limit therate of movement thereof.

3. In a grinding machine having a work support and a grinding wheelsupport, means for effecting relative transverse and longitudinalmovement between said supports, said transverse moving means comprisinga feedscrew and nut, a hydraulic motor for rotating" one of saidmembers, a reversing mechanism for said longitudinal moving means, anautomatic feed valve actuated by said reversing mechanism, a shuttlevalve of fixed capacity in excess of maximum requirements actuated bysaid automatic feed valve for supplying a measured maximum quantity offluid under pressure to said feedscrew operating motor at each reversalof said longitudinal moving means and a selector valve between saidshuttle valve and said screw operating motor for preventing operationthereof at one or both ends of the movement of said longitudinal movingmeans, said selector valve having means for predetermining whether allor a portion of'said measured quantity of fluid reaches said feedscrewoperating motor, and a throttle valve in said selector valve fordetermining how much of the output of said shuttle valve is supplied tosaid feedscrew operating motor.

4. In a grinding machine having a work support and a grinding wheelsupport, means for effecting relative transverse and longitudinalmovement between said supports, said transverse moving means comprisinga feedscrew and nut,

a hydraulic motor for rotating one of said mec h anisms, a reversingmechanism for said longitudinal moving means, an automatic feed valveactuated by said reversing mechanism, a shuttle valve of fixed capacityin excess of maximum requirements actuated by said automatic feed valvefor supplying a measured maximum quan-' tity of fluid under pressure tosaid feedscrew operating motor at each reversal of said longitu dinalmoving means, means including an adjus= table restriction for directinga predetermined portion of the output of said shuttle valve to saidfeedscrew operating motor, and a selector valve between said shuttlevalve and said screw operating motor for preventing operation thereof atone or both ends of the movement of said longitudinal moving means.

5. In a grinding machine having a work support and a grinding Wheelsupport means for effecting relative transverse and longitudinalmovement between said supports, said transverse moving means comprisinga feedscrew and nut, a hydraulic motor for rotating one of said members,a reversing mechanism for said longitudinal moving means, an automaticfeed valve actuated by said reversing, mechanism, a shuttle valve offixed capacity in excess of maximum requirements actuated by saidautomatic feed valve for supplying a measured maximum quantity of fluidunder pressure to said feedscrew operating motor at each reversal ofsaid longitudinal moving means and a selector valve between said shuttlevalve and said screw operating motor for preventing operation thereof atone or both ends of the movement of said longitudinal moving means, saidselector valve having means for predetermining whether all or a portionof said measured quantity of fluid reaches said feedscrew operatingmotor, and means for by-passing the fluid not used for said motor.

RALPH E PRICE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,022,542 Flygare et al Nov. 26,1935 2,127,877 Maglott Aug. 23, 1938 2,335,356 Price et a1 Nov. 30, 1943

